The cold-welding process requires no heat input to join metal pieces together. The metal remains in the solid phase, and it is not molten at any time. So, cold welding is considered to be a solid-state welding process. The applied pressure brings the surfaces of the workpieces together as close as possible. Once pressed together, the nanoscale distance becomes irrelevant, and metal atoms jump from one piece to another. This results in a near-perfect bond with almost no repercussions, and the two separate pieces of metal become a homogeneous mass. But to achieve this, you need to clean the metal surfaces to perfection. Every metal has oxide layers that must be removed before attempting to cold weld.

• Refurbishment of damaged metallic structure without introduction of heat and machining.

• A viable alternative is the use of epoxy composites that bond strongly to the flange sealing face, and thus completely isolating it from the operating environment.

• The material discussed here is an epoxy-based composite for metal repair. The system is cold applied and does not require hot work or specialist equipment. The risk of sparks is furthermore eliminated by minimized surface preparation requirements. Once mixed and applied, the epoxy pastes grade composite acts as a permanent gasket, having excellent compressive strength as per ASTM testing.